Endotracheal tube

ABSTRACT

An endotracheal tube includes a proximal tube shaft and a distal tube shaft coupled to the proximal tube shaft. The proximal tube shape defines a proximal lumen and the distal tube shaft defines a distal lumen extending from the proximal lumen. The distal tube shaft includes two or more curved portions configured to be inserted into the trachea when the tube is inserted into a patient. The proximal tube shaft includes a substantially straight or a slightly curved portion. A method of intubating a patient includes advancing a tube having a distal portion with at least two curved portions into the trachea of the patient, and delivering gas through the tube to the patient&#39;s lungs.

This application is a continuation of U.S. application Ser. No.10/375,019, filed Feb. 28, 2003 now U.S. Pat. No. 6,874,504, entitled“ENDOTRACHEAL TUBE,” which is incorporated by reference herein in itsentirety.

TECHNICAL FIELD

This description relates to an endotracheal tube.

BACKGROUND

An endotracheal tube is used during surgery that requires respiratoryassistance, typically for ventilation and/or the administration ofinhalation anesthesia through a patient's opened vocal chords into thetrachea. Additionally, an endotracheal tube can be used to assistventilation of a patient experiencing a respiratory crisis. Theendotracheal tube includes a connector that connects the endotrachealtube to a gas supply such that the gas flows from the supply through thetube to the lungs.

SUMMARY

In one general aspect, an endotracheal tube includes a proximal tubeshaft and a distal tube shaft coupled to the proximal tube shaft. Theproximal tube shaft defines a proximal lumen and the distal tube shaftdefines a distal lumen extending from the proximal lumen. The distaltube shaft includes two or more curved portions that are configured tobe inserted into the trachea when the tube is inserted into a patient.

Implementations may include one or more of the following features. Forexample, the proximal tube shaft includes a straight portion and aninlet at a proximal end of the shaft. The proximal lumen has a diametersized to accommodate a stylet.

The proximal tube shaft is made from a material that is able to returnto its original premolded shape following a flexure. The distal tubeshaft is made from a material that is able to return to an originalpremolded shape following a flexure. Either or both of the tube shaftsare formed of a material that conforms to the shape of a patient'strachea. The shafts are formed, for example, of a flexible thermoplasticmaterial.

The distal tube shaft is coupled to the proximal tube shaft by molding,by welding, or by gluing. The distal tube shaft may be coupled to theproximal tube shaft by integrally molding the distal tube shaft and theproximal tube shaft during manufacturing.

The distal tube shaft includes an inflatable cuff. The inflatable cuffcovers at least a portion of the two or more curved portions of thedistal tube shaft. The proximal tube shaft includes at least one curvedportion.

In another general aspect, an endotracheal tube includes a proximal tubeshaft defining a proximal lumen that extends along a central axis, and adistal tube shaft coupled to the proximal tube shaft and defining adistal lumen that extends along a central axis. The distal central axisincludes one or more inflection points. The portions of the distal tubeshaft on either side of the one or more inflection points are configuredto be inserted into a trachea of a patient when the tube is insertedinto the patient.

In another general aspect, a medical device includes a tube having adistal portion having at least two curved portions. The distal portionis configured for placement into a trachea of a patient. Implementationsmay include the following features. For example, the tube includes aproximal portion with a straight portion. The tube has an outer diameterin the range of about 0.6 to 2 cm. The tube has an outer diameter sizedto fit within the trachea. The tube defines a lumen for passage of agas. The lumen has a diameter in the range of about 2.5 to 9 mm.

In another general aspect, a method of intubating a patient includesadvancing a tube having a distal portion with at least two curvedportions into the trachea of the patient, and delivering gas through thetube to the patient's lungs. The method may further include maneuveringthe tube without the use of a stylet.

In another general aspect, a method for making an endotracheal tubeincludes providing a tube having a proximal portion defining a lumen anda distal portion defining a lumen extending from the proximal lumen, andforming the distal portion to include two or more curved portions. Themethod may further include forming the proximal portion with a straightportion and forming the distal portion to fit within a trachea of apatient when the tube is inserted into the patient. The method may alsoinclude forming an inflatable cuff over a portion of the two or morecurved portions of the distal portion.

Aspects of the techniques and systems may include one or more of thefollowing advantages. For example, the shape of the distal tube shaft,with the two or more curved portions, facilitates intubation of thepatient's trachea by enhancing maneuverability within the laryngealcavity during insertion. Furthermore, the shape of the distal tube shaftis contoured to track the shape of the trachea, thus limiting the riskof injury due to puncture of soft tissue surrounding the trachea. If astylet is used, the operator inserts the stylet into the proximal tubeshaft up to the distal tube shaft, but the operator need not insert thestylet within the distal tube shaft. Thus, the risk of injury is reducedbecause the tissue of the trachea is contacted by the relatively softdistal end of the tube rather than the end of a stylet, which canaccidentally protrude from the tube if the stylet is positioned withinthe distal tube shaft.

Other features and advantages will be apparent from the description, thedrawings, and the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 shows an endotracheal tube according to the invention.

FIG. 2 shows a cross-sectional view of the endotracheal tube of FIG. 1taken along section 2—2.

FIG. 3 shows a cross-sectional view of the endotracheal tube of FIG. 1taken along section 3—3.

FIG. 4 shows the curvature of the endotracheal tube of FIG. 1.

FIG. 5 shows the curvature of a distal portion of the endotracheal tubeof FIG. 1.

FIG. 6 shows the endotracheal tube of FIG. 1 inserted into a patient.

FIG. 7 shows an endotracheal tube according to the invention.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Referring to FIG. 1, an endotracheal tube 100 includes a proximal tubeshaft 105, which is nearer the operator, and a distal tube shaft 110,which is inserted into the trachea of a patient. The distal tube shaft110 connects with the proximal tube shaft 105 at an imaginary plane(depicted by line 130). The proximal tube shaft 105 has a central axis125 (see also FIG. 2). The distal tube shaft 110 has a central axis 140(see also FIG. 3). The two axes meet at the plane 130. The proximal tubeshaft 105 is shaped with a substantially straight or a slightly curvedportion, as described further below. The distal tube shaft 110 is shapedwith a first curved portion that is concave in a first direction and asecond curved portion that is concave in a second direction distinctfrom the first direction, as described further below. The shape of thedistal tube shaft provides, in three dimensions, flexibility, movementand control of the distal region of the endotracheal tube. This providesfor safe, efficient, and quick intubation, that is, insertion of theendotracheal tube (in particular, the distal region of the endotrachealtube) into the trachea.

The proximal tube shaft 105 defines a proximal lumen 115 and an inlet127 for flow of gas into the proximal lumen 115. The distal tube shaft110 defines a distal lumen 135 in fluid communication with the proximallumen 115 for flow of gas from the proximal lumen 115 to the distallumen 135. The distal tube shaft 110 terminates in a beveled end 150having an outlet 155 for flow of gas out of the distal lumen 135.Additionally, the distal tube shaft 110 defines an opening 160 throughthe wall of the tube for flow of gas out of the distal lumen 135.

The endotracheal tube 100 typically includes an inflatable cuff 165 onthe exterior of the distal tube shaft 110 near the plane 130. Wheninflated, the cuff 165 hugs the interior walls of the trachea tomaintain the position of the endotracheal tube 100 within the trachea.The inflatable cuff 165 is inflated through a channel 166 that isseparately formed within the proximal tube shaft 105 (see also FIG. 2).The channel 166 is connected to a checking device 167 for regulating theinflation pressure of the cuff 165. The endotracheal tube 100 alsoincludes a connector 180 (for example, a Luer-locking connection) on theproximal tube shaft 105 that connects to a gas supply (not shown).

Referring to FIG. 4, the proximal tube shaft 105 is shaped with asubstantially straight or a slightly curved portion 450.

Referring also to FIG. 5, the distal tube shaft 110 is shaped with twoor more curved portions 550, 555 such that the distal axis 140 isconcave in two or more distinct directions. For example, curved portion550 is concave as viewed from the right in FIG. 5, and curved portion555 is concave as viewed from the left in FIG. 5. Therefore, the distalaxis 140 passes through at least one inflection point (such as point430), which defines the plane at which the curved portion 550 meets thecurved portion 555. Along the curved portion 550, the axis 140 follows acurve having a radius of curvature suitable with the size and shape ofthe trachea into which the distal tube shaft 110 is inserted. Along thecurved portion 555, the axis 140 follows a curve having a radius ofcurvature suitable to the size and shape of the trachea into which thedistal tube shaft 110 is inserted. The curved portion 550 is preferablyoriented opposite to the curved portion 555, as shown in the figures.Thus, the amount of bend in the curved portions 550, 555 is limited bythe size of the trachea. For simplicity, the axis 140 is shown totraverse a two-dimensional path; however, the axis 140 may traverse athree-dimensional path.

The tube shafts 105 and 110 are each made from materials havingsufficient memory and resiliency to return to their respective premoldedshapes following a flexure. Additionally, the tube shafts 105 and 110are made from materials that enable the tube shafts 105 and 110 toconform to the shape of the patient's laryngeal cavity and trachea,rather than forcing the trachea to conform to the shapes of the tubeshafts 105 and 110. The materials are selected such that the tube shafts105 and 110 do not kink during use. The tube shafts 105 and 110 can bemolded individually as separate pieces and then joined together usingany suitable technique, such as, for example, a glue seal, a weld seal,a mold, or an interference fit. The joining technique can be selecteddepending on the materials selected for the tube shafts 105 and 110.Alternatively, tube shafts 105, 110 can be molded from a single tube.

Suitable materials for the tube shafts 105 and 110 include flexiblethermoplastic materials such as, for example, polyvinylchloride, andpolyethylene. Furthermore, the distal tube shaft 110 can be made from amaterial that is rigid enough to retain its shape upon entering thepatient's trachea, soft enough to prevent injury to the patient'strachea and to prevent kinking of the shaft 110.

The distal tube shaft 110 is sized to fit within the trachea, which canvary in diameter from 0.5 to 2.5 cm. Accordingly, the outer diameter ofthe distal tube shaft 110 will be smaller than the smallest diameter ofthe trachea of the patient to be anesthetized. For example, the outerdiameter of distal tube shaft 110 can range between approximately 0.6 to2 cm. The distal tube shaft 110 has a length (labelled as 570 as shownin FIG. 5) and the tube 100 has a total length (labelled as 470 as shownin FIG. 1) to enable the operator to insert the entire distal tube shaft110 into the trachea upon insertion of the tube 100 into the patient. Inthis way, at least a portion of each of the curved portions 550, 555 iscovered by the inflatable cuff 165. For example, the size of the distaltube shaft 110 and the tube 100 are selected depending on the patient'sage, sex, and/or size. In one implementation, the length 570 of thedistal tube shaft 110 is about 5 cm and the total length 470 of the tube100 is about 32 cm for use in an adult trachea. The total length 470 ofthe tube 100 is about 20 cm long for use in the trachea of a child. Thelumens 115, 135 have a diameter, for example, of about 2.5 to 9 mm, forpermitting an adequate supply of gas to flow to the patient's lungs, andfor receiving a stylet, as described below.

Referring to FIG. 6, in use, the operator inserts the beveled end 150 ofthe tube 100 into the mouth 605 of the patient and maneuvers the distaltube shaft 110 through the laryngeal cavity 610 and into the trachea600. During insertion, the operator can use an optical device such as alight source or a telescope or a mechanical guide device to maneuver thedistal tube shaft 110 through the laryngeal cavity 610 and into thetrachea 600. The operator then attaches the anesthesia supply (notshown) to the connector 180 of the tube 100.

The operator inflates the cuff 165 after intubation or at any suitabletime during intubation. In this way, the cuff 165 functions to hug thewall of the trachea and to protect the trachea and lungs againstaspiration of foreign substances, such as foreign bodies, food, ordigestive system contents. The operator then administers oxygen orinhalation anesthesia directly to the patient through the outlet 155 andthe opening 160. The opening 160 serves to ventilate the inhalationanesthesia if the outlet 155 becomes clogged.

Referring again to FIG. 1, though not required, during a procedure astylet 170 can be used in conjunction with the endotracheal tube 100.The stylet 170 is a semi-rigid wire, which maintains a preformed shapeuntil bent into another shape. The stylet 170 is sized to be receivedwithin lumens 115, 135. The operator inserts the stylet 170 into theproximal lumen 115 of the proximal tube shaft 105 until the stylet 170is at or near the plane 130. The operator can bend the stylet 170 into adesired shape after insertion into the endotracheal tube 100. The stylet170 provides rigidity to the otherwise flexible endotracheal tube 100,thus facilitating insertion of the proximal tube shaft 105 into thelaryngeal cavity 610 of the patient. The operator need not insert thestylet 170 into the distal tube shaft 110 because the shape of thedistal tube shaft 110 facilitates its passage into the trachea 600. Inthis way, the risk of injury to soft tissue and vocal chords surroundingthe trachea is reduced because the end of the stylet is prevented fromreaching the end 150 of the insertion within the tube 100.

The operator uses the stylet 170 to guide the distal tube shaft 110during insertion of the beveled end 150 into the mouth 605 of thepatient and maneuvering of the distal tube shaft 110 through thelaryngeal cavity 610 and into the trachea 600. The operator removes thestylet 170 from the endotracheal tube 100 when the tube 100 enters thevocal chords.

Other implementations are within the scope of the following claims. Forexample, the proximal tube shaft 105 may include one or more curvedportions. For example, as shown in FIG. 7, the proximal tube shaft 105has a curved portion that is concave in a single direction. The tubeshafts 105 and 110 can be molded as a single piece.

1. An endotracheal tube comprising: a proximal tube shaft defining aproximal lumen; and a distal tube shaft coupled to the proximal tubeshaft and defining a distal lumen extending from the proximal lumen, thedistal tube shaft having a wall defining a lateral opening in the wall;wherein the distal tube shaft includes two or more curved portionshaving concavities with distinct directions, the curved portions beingconfigured to be inserted into the trachea of a human when the tube isinserted into a human patient.
 2. The tube of claim 1 wherein theproximal tube shaft includes a straight portion.
 3. The tube of claim 1wherein the proximal tube shaft is made from a material that is able toreturn to an original premolded shape following a flexure.
 4. The tubeof claim 1 wherein the distal tube shaft is made from a material that isable to return to its original premolded shape following a flexure. 5.The tube of claim 1 wherein the proximal tube shaft is formed of amaterial that conforms to the shape of a patient's trachea.
 6. The tubeof claim 1 wherein the distal tube shaft is formed of a material thatconforms to the shape of a patient's trachea.
 7. The tube of claim 1wherein the proximal tube shaft is formed of a flexible thermoplasticmaterial.
 8. The tube of claim 1 wherein the distal tube shaft is formedof a flexible thermoplastic material.
 9. The tube of claim 1 wherein thedistal tube shaft and the proximal tube shaft are integrally molded as asingle piece.
 10. The tube of claim 1 further comprising a devicecovering at least a portion of the at least two curved portions of thedistal portion configured to maintain the position of the curvedportions within the trachea.
 11. The tube of claim 1 wherein thecovering device includes an inflatable cuff.
 12. The tube of claim 1wherein the proximal tube shaft includes at least one curved portion.13. An endotracheal tube comprising: a proximal tube shaft defining aproximal lumen that extends along a central axis; and a distal tubeshaft coupled to the proximal tube shaft and defining a distal lumenthat extends along a central axis, the distal tube shaft having a walldefining a lateral opening in the wall; wherein the distal central axisincludes one or more inflection points and portions of the distal tubeshaft on either side of the one or more inflection points are configuredto be inserted into the trachea of a human when the tube is insertedinto a human patient.
 14. A medical device, comprising: a tube includinga distal portion having at least two curved portions having concavitieswith distinct directions, the curved portions being configured forplacement into a trachea of a human patient, the tube defining a lumenfor passage of a gas, and the distal portion having a wall defining alateral opening in the wall.
 15. The medical device of claim 14 whereinthe tube includes a proximal portion with a straight portion.
 16. Themedical device of claim 14 wherein the tube includes a proximal portionwith at least one curve.
 17. A method of intubating a human patient,comprising: advancing an endotracheal tube having a distal portion withat least two curved portions having concavities with distinct directionsinto the trachea of the patient, and delivering gas through the tube tothe patient's lungs.
 18. The method of claim 17 wherein advancingincludes maneuvering the tube without the use of a stylet.
 19. Themethod of claim 17 further comprising manipulating the tube to maintainthe position of the tube within the trachea.
 20. The method of claim 19wherein manipulating the tube comprises inflating a cuff.